Chapter 7: Learning 1 What is learning? A relatively permanent change in behavior due to experience...

Post on 27-Dec-2015

217 views 2 download

Tags:

Transcript of Chapter 7: Learning 1 What is learning? A relatively permanent change in behavior due to experience...

Chapter 7:Learning

1

• What is learning?

• A relatively permanent change in behavior due to experience

• First test - purpose?

• To assess learning

• First test in relation to the definition of learning.

2

• Three types of learning: Classical Conditioning

Operant Conditioning

Learning by Observation (Observational Learning)

• Classical Conditioning

• A type of learning in which the learner comes to associate two stimuli.

3

4

Classical Conditioning

• Pavlov - Russian physiologist.

• Studied physiological responses in dogs.• Question?

• Hypothesis:

If a neutral stimulus is paired with a stimulus which automatically produces a response,

then the neutral stimulus comes to produce the same response.

5

Conditioned Stimulus (N)

Unconditioned Stimulus

Food

Unconditioned Response

Bell/buzzer

Salivation

Conditioned Response

Salivation

Pavlov’s Experiments

• Extinction - the dying out of a response due to non-reinforcement.

6

• Generalization - responding to a stimulus

similar to but not exactly like the original conditioned stimulus

• Beep/boop

• Stimulus Discrimination - learning to

respond to one stimulus but not another

• Classical Conditioning and human learning

• John Watson in early 1900’s

• Famous “Little Albert” experiment.

7

Conditioned Stimulus (N)

Unconditioned Stimulus

Loud Noise

Unconditioned Response

White Rat

Fear

Conditioned Response

Fear

Little Albert Experiment

• Could Watson have deconditioned “little Albert”?

• Possibly so, but he did not get the opportunity.

8

Conditioned Stimulus (N)

Unconditioned Stimulus

Food Friend Fun

Unconditioned Response

White Rabbit

No Fear Positive Feeling

Conditioned Response

Positive Feeling

• Mary Jones - Peter

• Peter was afraid of a white rabbit

• She decided to decondition Peter so he would no longer fear the white rabbit

• Used classical conditioning principles.

Updating Pavlov’s Understanding

• Cognitive Processes.

• What may be learned is a mental expectancy

• animal expects that food will follow the bell

• Thus, the dog anticipates and salivates to the bell.

9

• Biological Predispositions.

• At one time, it was thought that any stimulus could be used as a conditioned stimulus with equal success

• However, John Garcia working with rats did not find support for this

• He used three stimuli as CSs:

- a sound

- a sight (something the animal saw)

- a taste (something with a distinctive taste).10

• For example:

11

a sound

a picture

bad tasting water

radiation treatment

radiation treatment

radiation treatment sickness

sickness

sicknessCS UCS UCR

• Which of these CSs will result in avoidance behavior in the rat?

• Why? Biological predisposition.

12

• What do humans learn through classical conditioning that is significant to personality?

• Examples

• Assume little Johnny is afraid to go to the doctor’s office. What would the CS, UCS, UCR, and CR be?

• CS - _________; UCS - __________

• UCR - _________; CR - __________

Operant Conditioning

• B.F. Skinner

• Involves operant behavior

• Implies operate as in operating or behaving

• Behavior operates on the environment to produce consequences.

13

• What consequences occur after we behave?

• Rewards (reinforcement) or punishment

• Reinforcement - that which follows behavior and makes that behavior more likely to occur again

• Effect of reinforcement - increases rate of responding

• Two types of reinforcement:

positive reinforcement

negative reinforcement.

14

15

Positive Reinforcement• Positive Reinforcement - something positive or pleasant

is added to the environment after a response

• Is positive reinforcement if . . .

it increases rate of responding

• Rat in Skinner box

• When would shaping be used?• To condition complex behavior. Another Example.

• Primary and secondary reinforcers

• Shaping - reinforcing successive approximations of the desired response

16

Schedules of Reinforcement• Continuous schedule

• Partial schedules:

1. Fixed ratio (FR)

2. Variable ratio (VR)

3. Fixed interval (FI)

4.Variable interval (VI)

• Why did Skinner study different schedules of reinforcement?

• To determine what effect different schedules have on rate of responding.

17

Negative Reinforcement• What effect does negative reinforcement have

on rate of responding?

• Increases rate of responding

• Remember: reinforcement, whether positive or negative, increases rate of responding

• How would you get a rat in a Skinner box to press the lever using negative reinforcement?

18

• Negative reinforcement - removing something aversive (unpleasant) after a response has been made.

• Is negative reinforcement if

it increases rate of responding

• Thus, to use negative reinforcement – must have something aversive which can be removed

• Give examples using human behavior.

19

Punishment• What effect does punishment have on rate of

responding?

• Punishment decreases rate of responding

• Two types of punishment:

1) Adding something aversive to the environment after a response has been made. Is punishment if it . . .

decreases rate of responding. Examples.

20

2) Removing something pleasant (reinforcing) after a response has been made. Is punishment if it . . .

decreases rate of responding

• Examples

• Drawbacks to punishment:

1) Punished behavior is not forgotten, but suppressed. Child learns when misbehavior will and will not be punished

2) If behavior is only occasionally followed by something aversive, rate of responding may not decrease. Example.

21

3) Can create fear by process of association (classical conditioning)

4) May provide a model of aggression as a way to deal with problems

5) Does not tell a child what to do, rather it communicates what not to do. Thus, mild punishment combined with reinforcement for appropriate behavior is usually advocated.

Updating Skinner’s Understanding• Cognitive Processes

• Learning can occur without reinforcement

• Latent learning – learning exhibited long after learning has occurred. Stored in memory & used later.

• Overjustification Effect - giving a reward for engaging in behavior that one already likes to do – may make behavior less likely.

• Biological Predisposition. 22

Comparing Classical and Operant Conditioning

• Both involve learning by association

• In classical conditioning, we learn to associate two stimuli (a CS and a UCS)

• In operant conditioning, we learn to associate a response and its consequence and thus . . .

• repeat acts followed by rewards and avoid acts followed by punishment.

23

Observational Learning

• We imitate our models• Soon after birth… p. 342• Observational learning - Albert Bandura • Learning by observing others• Modeling - process of observing and imitating a

specific behavior.

24

25

Bandura’s Classic Bobo Doll Experiment:• Bandura made a film with aggressive model

attacking a Bobo doll

• Punched doll, hit doll with hammer, kicked doll

• Nursery school children randomly assigned to one of three groups

1. Model rewarded group

2. Model punished group

3. No consequence group.

26

• After viewing model (film), each child was allowed to play in playroom

• Dependent variable - aggressive behavior

• Which group was more likely to imitate the aggressive model’s behavior?

• It was the model rewarded group and also the no consequence group

• Implications for our society today.

Things you would want to do if you wanted to create a violent society:

1. Expose children from little up to much violent behavior which is portrayed in an exciting way (aggressive models)

2. Allow these children to play violent video games where killing is rewarded and fun

3. This may desensitize children to violence- it’s not so bad, it’s even fun.

27

4. Provide young people with easy access

5. Frustrate and ostracize young people so they are loners, not a part of in-group

6. Do not teach children to value human life and to respect others.

28